Welcome and Purpose of the Mini-Workshop

• Masashi Hazumi (National Central University)

Room: Chien-Shiung Building (Physics Building) room 209

Enhancing the Dynamic Range of Quantum Sensing via Quantum Circuit Learning

• Yuichiro Matsuzaki (Chuo University)

Room: Chien-Shiung Building (Physics Building) room 209 abstract: Quantum metrology is a promising application of quantum technologies, enabling the precise measurement of weak external fields at a local scale. In typical quantum sensing protocols, a qubit interacts with an external field, and the amplitude of the field is estimated by analyzing the expectation value of a measured observable. Sensitivity can, in principle, be enhanced by increasing the number of qubits within a fixed volume, thereby maintaining spatial resolution. However, at high qubit densities, inter-qubit interactions induce complex many-body dynamics, resulting in multiple oscillations in the expectation value of the observable even for small field amplitudes. This ambiguity reduces the dynamic range of the sensing protocol. We propose a method to overcome the limitation in quantum metrology by adopting a quantum circuit learning framework using a parameterized quantum circuit to approximate a target function by optimizing the circuit parameters. In our method, after the qubits interact with the external field, we apply a sequence of parameterized quantum gates and measure a suitable observable. By optimizing the gate parameters, the expectation value is trained to exhibit a monotonic response within a target range of field amplitudes, thereby eliminating multiple oscillations and enhancing the dynamic range. This method offers a strategy for improving quantum sensing performance in dense qubit systems. Kawaguchi, H., Mori, Y., Satoh, T., & Matsuzaki, Y. (2025). Enhancing the Dynamic Range of Quantum Sensing via Quantum Circuit Learning. arXiv preprint arXiv:2505.04958.

Quantum Sensing at the CHRONOS Project

• Yuki Inoue (National Central University)

Room: Chien-Shiung Building (Physics Building) room 209

Photo session Room: Chien-Shiung Building (Physics Building) room 209

Hint of Ultra-Light Axionlike Dark Matter and Future Measurements with Diamond Quantum Sensors

• Masashi Hazumi (National Central University)

Room: Chien-Shiung Building (Physics Building) room 209

Quantum speed limits and selected applications in quantum many-body physics and quantum information science

• Jyong-Hao Chen (National Central University)

Room: Chien-Shiung Building (Physics Building) room 209

Development of Josephson Parametric Amplifiers for Axion Search and Quantum Information Applications

• Yung-Fu Chen (National Central University)

Room: Chien-Shiung Building (Physics Building) room 209

Quantum Technology Strategy in Taiwan

• Ming-Jye Wang (ASIoP)

Room: Chien-Shiung Building (Physics Building) room 209

Free Discussion on Future Directions Room: Chien-Shiung Building (Physics Building) room 209